In recent years, various data communication methods, such as the 3rd Generation (3G) or 4th Generation (4G) mobile telecommunication network method, fixed wireless communication standards, such as Worldwide Interoperability for Microwave Access (WiMax™), and Wireless Local Area Network (WLAN) standards, such as Wireless Fidelity (WiFi™) et al, have been proposed. Some of these data communication methods are free, and others require a user to pay for the service. Consequently, a communication controlling method for switching networks easily between data communication methods is needed.